Effect of osaterone acetate administration on prostatic regression rate, peripheral blood hormone levels and semen quality in dogs with benign prostatic hypertrophy.
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The effects of osaterone acetate (OSA), which is an anti-androgen agent being developed as a therapeutic drug for benign prostatic hypertrophy (BPH) in dogs, on the degree of prostatic regression and semen qualities were investigated. Prostatic regression was compared between dogs with and without orchidectomy. Five male beagles aged 5-9 years were used in the experiment. OSA was orally administered at doses of 0.2 mg/kg and 0.5 mg/kg for one week. The prostatic regression rate one week after the end of administration was 62.6% on average. In the orchidectomized group, the mean regression rate one week after orchidectomy was 60.1%. However, the prostate became enlarged 6 months after administration, compared to the size prior to administration. The above findings suggested that OSA is clinically applicable as a therapeutic drug for BPH in dogs, and inhibits prostatic hypertrophy during the early phase. (+info)
The effects of chlormadinone acetate (CMA), antiandrogen, on the pituitary, testis, prostate and adrenal gland of the dog with spontaneous benign prostatic hyperplasia.
(10/52)
The effect of chlormadinone acetate (CMA), a synthetic steroidal antiandrogen, on spontaneous benign prostatic hyperplasia (BPH) in dogs was investigated. Male beagle dogs (5-8 years old) were divided into four experimental group. Group 1 consisted of untreated controls. Groups 2 and 3 received CMA 0.03 and 0.1 mg/kg/day, p.o., respectively, for 6 months. In group 1, glandular hyperplasia of the prostate was clearly detected. The glandular epithelial cells showed uniformly intense nuclear staining for androgen receptor (AR). AR was also localized in the nuclei of the fibro-muscular stromal cells. In groups 2 and 3, CMA produced marked atrophy of the glandular epithelium. The interacinar fibro-muscular stroma was prominent. The nuclear staining for AR in both epithelial and stromal cells was remarkably decreased. In addition, a histopathological study showed that CMA medication for 6 months exerted no effect on the testes and adrenal glands or on immunoreactive positive cells to LH- and ACTH-antibody (pituitary LH- and ACTH-cells). Therefore, it is concluded that CMA (0.03 and 0.1 mg/kg) causes regression of spontaneous canine BPH without any histopathological effects on the testes, adrenal glands or pituitary LH- and ACTH-cells. (+info)
Pharmacokinetics and biliary excretion of osaterone acetate, a new steroidal antiandrogen, in dogs.
(11/52)
The pharmacokinetics and biliary excretion of osaterone acetate (17alpha-acetoxy-6-chloro-2-oxa-4,6-pregnadiene-3,20-dione; OA), a new steroidal antiandrogen, were investigated in intact dogs and biliary fistula dogs after bolus intravenous administration of (14)C-labeled drug. In intact dogs, OA exhibited a biexponential disposition with a very long half-life of 197.9 +/- 109.9 h. OA accounted for almost all the plasma radioactivity. The major route of excretion was in feces via the bile. One-third of the radioactivity in the bile was due to OA. The major biliary metabolite was identified as a glucuronide of 17alpha-acetoxy-6-chloro-21-hydroxy-2-oxa-4,6-pregnadiene-3,20-dione. A significant amount of biliary recycling occurs in dogs. (+info)
Low serum testosterone level predicts worse response to endocrine therapy in Japanese patients with metastatic prostate cancer.
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Patients with prostate cancer generally respond to androgen withdrawal therapy, but progression to androgen-independence is frequently observed later. To examine whether pretreatment serum androgen status could predict disease progression in metastatic prostate cancer, pretreatment serum testosterone, histological grade, extent of bony metastasis, serum prostate-specific antigen (PSA) response to hormone therapy, and prognosis of the 40 patients with untreated metastatic prostate cancer who received endocrine therapy were evaluated. Although there were no differences in age, pretreatment PSA level, extent of bony disease and histological grade between patients with normal testosterone and those with low testosterone, PSA response after endocrine therapy was better in normal testosterone group. There was a significantly longer interval to disease progression in patients with normal testosterone than in those with low testosterone. The patients with metastatic prostate cancer with low serum testosterone were in the high risk group of worse response to endocrine therapy. Additional therapy might be considered in those patients. (+info)
Neoadjuvant hormonal therapy prior to radical prostatectomy: evaluation of pathological downstaging and biochemical relapse.
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OBJECTIVES: The effect of neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy (RP) on pathological downstaging of prostate cancer and biochemical relapse of serum prostate specific antigen (PSA) level was evaluated. MATERIALS AND METHODS: Twenty selected patients with prostate cancer, who were treated with hormonal therapy and demonstrated biochemical downstaging by reduction of PSA prior to RP and bilateral pelvic node dissection at the Tohsei National Hospital between January 1997 and August 2001, are reported on. The complete RP specimens of these 20 men were used for accurate evaluation of the pathological stage. All 20 patients received NHT; ten patients were treated with leuprolide plus flutamide and 10 received leuprolide plus chlormadinone acetate (CMA). RESULTS: Decreases in serum PSA values were demonstrated from a pre-hormonal average of 49.7 ng/ml to an average of 0.52 ng/ml after NHT. Of the three clinical stages, A2-C, for cancer patients, two of the 20 patients had stage A2, two had stage B1, nine had stage B2, and seven had stage C. Of the 20 patients with biochemical downstaging, two had pathological stage B1, seven had pathological stage B2, eight had pathological stage C, and three had positive pelvic lymph nodes. Ten (50%) of the 20 patients were reported to have positive surgical margins. Seminal vesical extension was observed in two cases, and penetration was not observed. Positive nodes were identified in three (15%) patients. Among the seven clinical stage C patients, one had pathological stage B1 disease and two had pathological stage B2. Four of nine patients with clinical stage B2 prostatic cancer had pathological stage C disease. The actuarial incidence of a rising PSA at 3 years for the leuprolide plus CMA group was 28.9% compared with 37.5%for the group receiving leuprolide plus flutamide. The cases of biochemical relapse did not necessarily indicate a high stage and had no tendency to be high for baseline PSA level, positive margin rates or Gleason scores. CONCLUSIONS: A significant decrease in the rate of penetration could be observed after NHT, though it was not so effective for pathological downstaging, and changes in the preoperative PSA level did not predict those patients who might have a favorable result. (+info)
Long-term prevention of estrus in the bitch and queen using chlormadinone acetate.
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Estrus was prevented with weekly oral administration of 2 mg chlormadinone acetate for 2.0 to 9.8 y in bitches and queens. Abnormalities, including mammary or uterine disorders, or both, were noted in 7 out of 14 bitches and 9 out of 24 queens during this long-term treatment. (+info)
The effects of new steroidal anti-androgen, TZP-4238, and chlormadinone acetate on the pituitary, prostate and adrenal gland of the rat: histopathological and immunocytochemical studies.
(15/52)
The atrophic effects of a synthetic steroidal anti-androgen, TZP-4238, on the pituitary, prostate and adrenal gland of rats were investigated. Male Sprague-Dawley rats were divided into three experimental groups. Group 1 consisted of controls. Groups 2 and 3 received chlormadinone acetate (CMA) 50 mg/kg/day and TZP-4238 10 mg/kg/day p.o., respectively, for 3 weeks. CMA (Group 2) produced marked atrophy of the prostate. Furthermore, CMA caused marked atrophy of the adrenal gland. Histopathologically, the remarkable atrophy was observed in the adrenal cortical cells of zonae fasciculata and reticularis. The most striking ultrastructural alterations were noted in the mitochondria. In addition, intramitochondrial localization of glutathione-peroxidase (GSH-PO) which effectively reduces the lipid peroxides, was less than that in the controls. In the anterior pituitary gland, CMA induced a reduction in the size of ACTH cells. TZP-4238 (Group 3) produced marked atrophy of the prostate. However, TZP-4238 exerted no effect on the adrenal gland or anterior pituitary ACTH cells. In addition, the present histopathological study showed that TZP-4238 or CMA exerted no effect on the testes or anterior pituitary LH cells. Therefore, it is suggested that TZP-4238 causes atrophy of the prostate without any significant histopathological changes in the adrenal glands or anterior pituitary ACTH cells under the present experimental conditions. We further speculated that TZP-4238 had a more potent anti-prostatic effect than CMA and TZP-4238 had a less inhibitory influence than CMA on the pituitary-adrenal axis. (+info)
Dural arteriovenous malformation and sinus thromboses in a patient with prostate cancer: an autopsy case.
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A 67-year old man with prostate cancer showed Balint's syndrome, memory disturbance, anosognosia and hallucinations after having been comatose. Radiological findings indicated bilateral dural arteriovenous malformation (DAVM) and thrombosis at the bilateral transverse sinuses and superior sagittal sinus. Pathological findings showed abnormally dilated veins, diffuse neuron loss and gliosis in the parieto-occipital lobe. The chlormadinone and prostate cancer are speculated to have caused the dural sinus thrombosis which probably induced the DAVM. (+info)